Laundry drier control system



p 195s R. E. JACKSON 2,852,241

LAUNDRY DRIER CONTROL SYSTEM I Filed Feb. '7, 1957 iiillllll! l //v V NTO 1?. Rosier E. JACKSON BY HAS HTTORNEYS. HARE/5, lf/scH, Fosrzre 62 HAP/81s United States Patent 2,852,24l LAUNDRY DRIER CONTROL SYSTEM Robert E. Jackson, West Covina, Calif., assignor to Challenge Manufacturing Co., Los Angeles, Calif., a corporation of California Application February 7, 1957, Serial No. 638,733

2 Claims. (Cl. 263-19) The present invention relates in general to laundry driers, or similar apparatus, and a primary object of the invention is to provide an apparatus of this character which includes control means responsive to the temperature at a single, preselected point for interrupting the generation of heat in response to malfunctioning or improper operation of one or more of several components of the apparatus.

In general, the invention contemplates a laundry drier, and more particularly a commercial laundry drier, which includes a housing providing a drying chamber, means providing a combustion chamber, blower means for supplying combustion air to the combustion chamber, means providing an inlet passage in communication with the combustion and drying chambers for conveying products of combustion from the combustion chamber to the drying chamber, secondary air inlet means in the inlet passage intermediate the combustion and drying chambers for introducing secondary air into the inlet passage for admixture with the products of combustion from the combustion chamber, means providing an outlet passage in communication with the drying chamber, exhaust blower means for propelling air, products of combustion and water vapor from the drying chamber through the outlet passage, and supply means for delivering fuel to the combustion chamber.

The invention further contemplates, and an object thereof is to provide, a laundry drier wherein the inlet passage includes an inlet duct communicating at one end with the drying chamber and provided at its other end with an upstream facing scoop, the inlet passage further including a combustion chamber outlet which communicates with the combustion chamber and which extends into the scoop, the combustion chamber outlet and the scoop being spaced apart transversely of the inlet passage to provide the, aforementioned secondary air inlet means.

-An important object of the invention is to provide a laundry drier having means responsive to the temperature within the inlet passage at the secondary air inlet means and, more specifically, responsive to the temperature within the scoop forming the secondary air inlet means, for interrupting the supply of fuel to the combustion chamber whenever such temperature exceeds a predetermined value. a The foregoing temperature responsive means 'acts as a safety device cutting off the flow of fuel to the combustion chamber in response to malfunctioning or improper operation of one or more of several components of the drier, which is an important feature. For example, the aforementioned temperature responsive means, located as hereinbefore specified, cuts off the flow of fuel in response to a temperature rise in the inlet passage resulting from an increase in fuel pressure. As another example, the foregoing location for the temperature responsive means causes such means to cut off the flow of fuel in the event of burning out of the combustion chamber outlet leading to the scoop with which the temperature responsive means-is associated. As a furtherexample,

the temperature responsive means, in the location mentioned, interrupts the fuel supply to the combustion chamber in response to any obstruction anywhere in the apparatus, or associated components, which tends torestrict excessively air flow through the apparatus, such as an obstruction anywhere in the inlet passage, an obstruction between the inlet passage and the outlet passage by laundry within the drying chamber, an obstruction in the outlet passage due to lint accumulations, or the like, or an obstruction due to lint accumulations, or other causes, in any ducting leading from the outlet passage to the exterior of a building in which the drier is disposed. As an additional example, the temperature responsive means of the invention terminates the flow of fuel to the combustion chamber in the event of failure of the exhaust blower means. Thus, the temperature responsive means mentioned, located as required by the present invention, responds to any condition of improper operation which results in an excessive temperature within the inlet p assage to the drying chamber at the secondary air inlet means, regardless of the nature of the condition produc ing such excessive temperature, which is an important feature.

Another object is to provide a temperature responsive means capable of sensing the temperature within the inlet passage which is mounted on the scoop externally thereof and which responds to the temperature of the structure of the scoop, thereby responding to the temperature within the inlet passage. A further object is to provide a temperature sensitive means of the foregoing nature comprising a switch in circuit with electrical means for operating a fuel valve, such switch producing closure of the fuel valve in response to an excessive temperature.

The foregoing objects, advantages, features and results of the present invention, together with various objects, advantages, features and results thereof which will be apparent to those skilled in the art in the light of this disclosure, or which are inherent in the original claims hereinafter presented, may be achieved with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the accompanying drawing, in which:

Fig. 1 is a plan view of a commercial laundry drier which embodies the invention;

Fig. 2 is a side elevational view of the laundry drier;

Fig. 3 is an enlarged, fragmentary sectional view taken along the arrowed line 33 of Fig. 1;

Fig. 4 is a fragmentary sectional view taken along the line 44 of Fig. 3; and i Fig. 5 is a fragmentary diagrammatic view of the electrical circuitry of the laundry drier of the invention.

In the drawing, the numeral 10 designates a housing which provides a drying chamber therein and which is tiltable relative to a supporting structure 12 between an operating position and a loading and unloading position about an axis 14. The tiltable housing 10 is shown in its operating position in the drawing, being tiltable in the counterclockwise direction, as viewed in Fig. 2 of the drawing, into its loading and unloading position. Access to the interior of the housing 10 is provided by a door, not shown, at the front 16 of the housing. Within the tiltable housing 10 is a basket or drum 18 adapted to tumble laundry to be conditioned or dried and accessible through the door mentioned, the drum 18 being rotatable about an axis perpendicular to the pivot axis 14.

Considering the manner in which heat is supplied to the interior of the housing 10 to dry or condition laundry being tumbled within the drum 18, the laundry drier of the invention includes a burner assembly 20 one of the elements of which is a combustion chamber 22. The latter is supplied with fuel, such as gas, oil, or the like,

through a pipe 24 having a fuel valve 26 therein, as shown diagrammatically in Fig. 5. Combustion air is supplied to the combustion chamber 22 by a blower or blower means 28 driven by a motor 30.

The products of combustion emanating from the combustion chamber '22 are conveyed to the drying chamber provided by the housing 10 through an inlet passage designated generally by the numeral 32. This inlet passage includes an inlet duct 34 one end of which communicates with the top of the housing 10 so as to circulate the products of combustion and heated air downwardly through the drum 18 in which laundry is being tumbled. The inlet duct 34 is provided adjacent the housing'li) with a joint 36 which opens when the housing 1% is tilted into its loading and unloading position and which closes when the housing is tilted into its operating position. At its upstream end, the inlet duct 34 is provided with an upstream facing scoop 38, which scoop may merely take the form of an enlargement of the upstream end of the inlet duct. The inlet passage 32 also includes a combustion chamber outlet 40 which communicates at one end with the combustion chamber 22 and which projects into the scoop 38, the combustion chamber outlet and the scoop being spaced apart transverselyof the inlet passage 32 to provide therebetween a secondary air inlet or secondary air inlet means 42. The combustion chamber outlet 40 comprises an inner cone 44 surrounded by an outer cone or shroud 46 which is spaced from the inner cone to provide a cooling air space therebetween.

As will be apparent, the flow of products of combustion from the combustion chamber 22 through the inner cone 44 into the scoop 38 and the inlet duct 34 results in aspiration of secondary air into the inlet duct through the space between the inner and outer cones 44 and 46 and the space between the outer cone and the scoop. Such secondary air is mixed with the products of combustion in the inlet duct 34 to reduce the temperature thereof to a value sufficiently low to condition or dry clothes within the drum 18 without overheating thereof. Such aspiration of air through the space between the inner and outer cones 44 and 46 also serves to cool the inner cone 44.

Communicating with the housing 10 adjacent the bottom thereof is an exhaust duct 48 a portion of which provides an exhaust blower housing 50 for an exhaust blower, or exhaust blower means, not shown, driven by an electric motor 52. The exhaust blower draws air, products of combustion and water vapor from the housing 10 to maintain continuous flow throughout the inlet passage 32, the housing 10 and the outlet passage provided by the exhaust duct 48, the mixture of products of combustion and secondary air flowing downwardly through the housing 10 and through the laundry being tumbled within the drum 18 to condition or dry same.

The invention provides means 54 responsive to the temperature in the inlet passage 32 at the secondary air inlet 42 for cutting off the fuel supply to the combustion chamber 22 whenever such temperature exceeds a. predetermined value. More particularly, the temperature responsive means 54 is mounted on one wall 56 of the scoop 38 and senses the temperature of such wall to respond to the temperature within the scoop. As shown diagrammatically in Fig. 5, the temperature responsive means 54 includes a thermostatic switch 58 which responds to the temperature of the wall 56 and which is adapted to open in response to a temperature rise to a predetermined maximum. This switch is effectively connected in series with a suitable electrical means, such as a solenoid 60, so as to produce closure of the fuel valve 26 in response to a temperature increase to the predetermined maximum. In the particular construction illustrated, opening of the switch 58 results in de-energization of the solenoid 60 to permit closure of the fuel valve 26. Various other safety devices may be connected in series with the fuel valve solenoid 60, a gap 62 having been leftinsthecircuit in Fig. to indicate this.

However, since such safety devices are not essential to a consideration of the present invention, a disclosure thereof herein is unnecessary.

As will be apparent, whenever the temperature sensed by the thermostatic switch 58 attains the predetermined maximum, the fuel supply to the combustion chamber 22 is cut off by closure of the fuel valve 26, irrespective of the condition causing the excessive temperature at the secondary air inlet. For example, such excessive temperature may result from burning out of the burner cone 44 and its encircling shroud 46 so that flame from the combustion chamber impinges more or less directly on the scoop 38. Also, if an obstruction to flow develops in the inlet duct 34, within the housing 15} itself, within the exhaust blower housing 50, or within the exhaust duct 43, the temperature at the secondary air inlet 42 will increase and, if it increases to the predetermined maximum, indicating a serious obstruction tofiow, the temperature responsive means 54 closes the fuel valve 26 to terminate the supply of fuel to the combustion chamber 22. Further, should lint accumulations obstruct flow through any exhaust conduit leading from the exhaust duct 48 to the exterior of the building in which the drier is disposed, or should an obstruction to flow develop therein for any other reason, the temperature at the secondary air inlet 42 will increase. Again, if this increase in temperature is sufliciently high, the temperature responsive means 54 will terminate the supply of fuel to the combustion chamber 22. As an incidental matter, should the exhaust blower fail to operate for any reason, the resulting curtailment of the flow through the drier will produce a temperature increase at the secondary air inlet 42 suflicient to cut off the fuel supply to the combustion chamber. Thus, as will be apparent, any condition having the eifect of elevating the temperature at the secondary air inlet 42 sufiiciently will result in interruption of the fuel supply. Consequently, the temperature responsive means 54, located at the secondary air inlet 42, acts as a safety device which prevents the delivery of fuel to the combustion chamber in response to malfunctioning or improper operation of one or more of numerous components of the drier, or associated components, which is an important feature of the invention.

Although an exemplary embodiment of the invention has been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiment Without departing from the spirit of the invention as defined by the claims which follow.

I claim as my invention:

1. In a laundry drier, the combination of: a housing providing a drying chamber; means providing a combustion chamber; means providing an inlet passage in communication with said combustion and drying chambers for conveying products of combustion from said combustion chamber to said drying chamber, said inlet passage being provided intermediate said combustion and drying chambers with secondary air inlet means for mixing secondary air with the products of combustion from said combustion chamber; means providing an outlet passage in communication with said drying chamber; supply means for delivering fuel to said combustion chamber; and means responsive to the temperature within said inlet passage at said secondary air inlet means and controlling said supply means for interrupting the supply of fuel to said combustion chamber whenever the temperature within said inlet passage at said secondary air inlet means exceeds a predetermined value, said temperature responsive means being mounted on a wall of said inlet passage externally of said inlet passage and adjacent said secondary air inlet means so as to respond to the temperature within said inlet passage by sensing the'temperature of said wall.

2. Ina laundry drier, the combination of: ahousing providing a drying chamber; means providing a combustion chamber; means providing an inlet passage in communication with said combustion and drying chamber for conveying products of combustion from said combustion chamber to said drying chamber, said inlet passage including an inlet duct communicating at one end with said drying chamber and provided at its other end with an upstream facing scoop, said inlet passage also including a combustion chamber outlet communicating with said combustion chamber and projecting into said scoop, said combustion chamber outlet and said scoop being spaced apart transversely of said inlet passage to provide therebetween an inlet for secondary air for admixture with the products of combustion from said combustion chamber; means providing an outlet passage in communication with said drying chamber; supply means, including a fuel valve, for delivering fuel to said combustion chamber; and means responsive to the temperature within said scoop and controlling said supply means for closing said fuel valve to interrupt the supply of fuel to said combustion chamber whenever the temperature within said scoop exceeds a predetermined value, said temperature responsive means being mounted on said scoop externally thereof so as to respond to the temperature within said scoop by sensing the temperature of the structure of said scoop.

References Cited in the file of this patent UNITED STATES PATENTS 2,227,666 Noack Jan. 7, 1941 2,604,313 Grantham July 22, 1952 2,606,014 Baumann Aug. 5, 1952 2,776,797 Suesserott Jan. 8, 1957 

